The primary objective of the proposed course is to provide an in depth and modern tutorial in visual system circuits: how they work, how they develop and why and how they degenerate in specific disease states. The format of this course has been developed and updated for >20 years, in order to deliver to the students the most comprehensive, modern and impactful training in vision science and more generally, to provide a framework for thinking about sensory systems. Daily research seminars from 2 world leaders in a specific discipline of visual neuroscience provide i) a comprehensive overview of specific subfields of the visual system including a history of their exploration, ii) modern understanding o progress in each area, critical issues, and matters arising. iii) substantial opportunity for interactions between students and instructors to share ideas, ask questions and receive feedback on research past, present and future. Overall, the course emphasizes development of specific lines of inquiry in the context of existing models and technical advances. A relatively new aspect (started in the 2013 course and planned for 2015 and thereafter) is a focus on diseases of visual system and approaches to repair diseased/damaged circuits. Instructors are chosen on the basis of their long-standing and/or particularly significant contributions to the field. Each instructor provides in- depth expertise in a specific area that complements the others and the instructors are clustered along themes or topics over 1-2 day spans to encourage thorough coverage of a subfield, controversies and all. Teaching ability and willingness to interact with students is also a serious consideration when inviting speakers. The trainees (~22) are chosen by the course directors from a larger pool of applicants. This course provides an unusual opportunity for scientists already in vision science to deepen their knowledge and formulate plans for their work and for those new to the system, to get up to speed with the history, models and modern techniques and understanding in vision science. All this makes them excellent candidates for driving their own lines of inquiry in visual neuroscience, evidenced by the large percentage of students that go on to run their own independent labs. The course has consistently made, and will continue to make particular efforts to include a diverse group of participants, being particularly mindful of the inclusion of women, US minorities and a good balance of national and international scientists.